1. Field of the Disclosure
The present disclosure relates to a power generation input device, and more particularly to a power generation input device, with a small cogging torque, that can be adjusted so that a desired manipulation feeling is obtained.
2. Description of the Related Art
To conserve energy and reduce weight, some recent power generation input devices are batteryless input devices. When an input manipulation is performed on this type of power generation input device, it generates electric power needed for the input manipulation itself. The power generation input device includes a magnet and a coil. The magnet or coil is operated in response to the input manipulation, generating an induced electromotive force.
This type of power generation input device is described, for example, as the power generation input device described in Japanese Unexamined Patent Application Publication No. 2012-164658.
The power generation input device described in Japanese Unexamined Patent Application Publication No. 2012-164658 will be described with reference to FIG. 33 to FIGS. 35A and 35B. FIG. 33 is a perspective view illustrating the outside shape of a power generation input device 900 described in Japanese Unexamined Patent Application Publication No. 2012-164658. FIG. 34 is an exploded perspective view illustrating the structure of a power generator 901 incorporated into the power generation input device 900 described in Japanese Unexamined Patent Application Publication No. 2012-164658. FIGS. 35A and 35B are drawings illustrating the seesaw motion of a moving part 910 described in Japanese Unexamined Patent Application Publication No. 2012-164658; FIG. 35A illustrates a state before the moving part 910 starts the seesaw motion, and FIG. 35B illustrates a state after the moving part 910 has performed the seesaw motion.
The power generation input device 900 described in Japanese Unexamined Patent Application Publication No. 2012-164658 is a pushbutton input device having a manipulation part 903, which can be pressed, at the top, as illustrated in FIG. 33. The power generation input device 900 incorporates the power generator 901 illustrated in FIG. 34. When the manipulation part 903 is pressed, the power generator 901 operates in response to the operation of the manipulation part 903, generating electric power. The power generator 901 has a moving part 910, which is formed so as to sandwich a magnet 990 between an upper layer 930 and a lower layer 940, and also has a U-shaped base 920, around which an exciting coil 911 is wound. Both ends of the U-shaped base 920 are inserted into and disposed between the upper layer 930 and the lower layer 940 so as to sandwich the magnet 990 between the ends. The moving part 910 can perform a seesaw motion with the magnet 990 taken as a center, as illustrated in FIGS. 35A and 35B. When the moving part 910 performs a seesaw motion as described above, a magnetic flux passing through the exciting coil 911 changes and a current is thereby generated in the exciting coil 911. The seesaw motion of the moving part 910 will be described below by taking a case, as an example, in which the upper layer 930 of the moving part 910 comes into contact with one end of the U-shaped base 920 and the lower layer 940 comes into contact with the other end of the U-shaped base 920 as illustrated in FIG. 35A, after which the upper layer 930 of the moving part 910 comes into contact with the other end of the U-shaped base 920 and the lower layer 940 comes into contact with the one end of the U-shaped base 920 as illustrated in FIG. 35B. In the state before the seesaw motion starts (see FIG. 35A), the upper layer 930 is magnetically attracted to the one end of the U-shaped base 920 and the lower layer 940 is magnetically attracted to the other end of the U-shaped base 920. When a seesaw motion is performed, the upper layer 930 and lower layer 940 are separated from the U-shaped base 920 against the magnetism. When the midpoint between the upper layer 930 and the lower layer 940 is exceeded, the upper layer 930 is magnetically attracted to the other end of the U-shaped base 920 and the lower layer 940 is magnetically attracted to the one end of the U-shaped base 920, shifting to the state illustrated in FIG. 35B.
During an input manipulation, however, a large force is needed to separate the moving part 910 from the U-shaped base 920 at the beginning of the manipulation and almost no force is needed at the end of the manipulation because the U-shaped base 920 attracts the moving part 910. That is, a cogging torque is generated during the manipulation, so it is difficult to adjust a manipulation feeling to a desired feeling and maneuverability may be worsened.